Carton opening knife



y 1956 R. HONEY 2,743,523

CARTON OPENING KNIFE Filed June 27, 1955 0 INV EN TOR. 1% ff 50 59- gy J6 8 J9 20 Jd J3 J7 J0 CARTON OPENING KNIFE Robert Honey, Los Angeles, Calif.

Application June 27, 1955, Serial No. 518,144

4 Claims. (Cl. 311-286) This invention relates to knives of the type used for opening paper cartons and like operations and more particularly to an improved form thereof characterized by automatic shielding of the cutting blade.

An object of the invention is to provide a knife structure for opening cartons and similar operations in which the cutting edge of the blade is constantly resiliently shielded by means which are displaced as an incident to use of the knife.

Another object of the invention is to provide a knife construction for opening cartons or like operations in which the cutting means comprises a razor blade replaceably mounted in a handle means.

Still another object vof the invention is to provide a knife for opening cartons and like operations comprising a handle means for replaceablysupporting a razor blade and a spring clip for retaining the blade mounted on the handle means and for serving as a resilient guard means to shield the edge of the blade except when the knife is being used.

With the above objects in view, together with such additional objects and advantages as may subsequently appear, the invention resides in the parts, and in the construction, combination and arrangement of parts described, by way of example, in the following specification of a presently preferred mode of execution of the invention; reference being had to the accompanying drawings which form a part of said specification and in which drawings:

Fig. 1 is a side elevation of a knife embodying the invention,

Fig. 2 is a top plan view of the knife shown in Fig. l; a portion being shown in section taken on the line 22 of Fig. 1,

Fig. 3 is a fragmentary side elevation showing the blade carrying portion of the knife as in use.

Fig. 4 is an end elevation taken at the left hand end of Fig. 1,

Figs. 5 and 6 are sectional views taken respectively, on the lines 55 and 6-6 of Fig. 1, and

Fig. 7 is an exploded View of the blade carrying end of the handle component and the parts associated therewith.

Referring to the drawings, the illustrated embodiment of the invention comprises a handle component 1 of elongated flattened configuration; the hand grip portion 2 thereof having a central web portion 3. For convenience, the various parts of the invention will be referred to as top, bottom, upper, lower, and the like with reference to Fig. l and without regard for any position the knife may occupy in use. The handle component is preferably formed of a plastic molding and in conformity with good molding design, the sections are made as thin as possible consistent with the required strength. The blade carrying portion of the handle component is generally indicated at 4 and includes a blade engaging face 5 disposed substantially in the medial plane of the handle component and extends upwardly from the lower edge of the handle and terminates at a horizontally extending recess 6 of suflicient size and depth to accommodate one side of the back member 7 of lnited States Patent 0.

'ice

a safety razor blade 8; the width of the face 5 being slightly greater than the width of the blade and the lower corner of the portion 4 being cut away on a wide curve as at 9 to expose a corner of the blade 3. Additionally, the face 5 is provided with outwardly projecting lugs 10, 10 at each end thereof adapted to engage the notches 11, 11 of the blade as well as corresponding notches 12, 12 formed in the ends of a blade retaining member 13 which overlies the opposite side of the blade 8 and which is provided with an elongated clearance groove 14 extending along its upper edge to afford clearance for the opposite side of the blade back member 7. Preferably, this retaining member is also formed as a plastic molding. The lower outer corner of the blade retaining member 13 is curved as at 15 to correspond with the curved end 9 of the handle component, and the member is of a thickness to bring the outer face thereof flush with the outer face of the handle component. Thus, it will be noted that when the blade is disposed between the handle component and the blade retaining member, it is supported over its entire face except for the corner portion which is exposed by the curved end faces 9'and 15.

The retainer member 13 is removably secured to the handleportion by a resilient metal clip 16 comprising a piece of sheet metal having upwardly extending spring arms 17, 17 at one end thereof which engage recesses 18 and 19 formed in the outer side faces of the handle component and retainer member, respectively; said arms ad jacent their upper ends being formed to provide slightly inwardly curved detent portions which engage complementarily formed surfaces in the recesses 18 and 19 (see Fig. 5). The clip member extends in a run 20 from the arms 17 toward the end of the blade carrying portion and is provided With a longitudinal slot 21 in alignment with the blade 8 and thence extends upwardly in a vertical run 22 to a second pair of spring arms 23, 23 which slightly frictionally engage recesses 24 and 25 formed in the upper outer corners of the member 13 and blade carrying portion 4; said recesses being open at their upper ends to permit sliding action of the arms 23, 23 therein as will be presently explained.

In Figs. 1 and 3 it will be noted that the run 22 of the clip member 26 extends beyond the curved ends 15 and 9 and thence extends upwardly in the plane of the distal end of the handle component in a curve which is of much lesser radius than the curved end faces 9 and 15. Thus when the clip is in repose as in Fig. 1, the exposed edge of the blade 8 is within the confines of the clip element. When the knife is in use (see Fig. 3), pressure on the outer portion of the run 22 will cause the clip to bend with resultant exposure of the corner of the blade edge through the slot 21. Thus, in cutting open a carton, pressure on the side of the carton will project the corner of the blade into cutting engagement with the carton; the sliding engagement of the arms 23, 23 with their respective recesses serving to permit the necessary bending of the run 21) of the clip (see Fig. 3). When pressure on the carton or other surface ceases, the clip will return to its blade guarding position. When a blade edge becomes broken or dull, the clip is readily removed and the blade turned end for end to permit the other end to be used or to be replaced by a new blade as required. it is to be noted that the novel design comprised only three parts other than the blade and that these parts need not be assembled until the device is first supplied with a blade. Still further, the automatic guarding of the blade makes the device safe to handle when not in use and in the event of the knife slipping while being used, the blade is instantly guarded as soonas pressure thereon ceases. A further advantage lies in the fact that the depth of cut is limited and that there is consequently no danger of damaging the contents of a carton being cut open.

While the foregoing specification discloses a presently preferred form of the invention, it is not to be inferred that the invention is limited to the specific form so disclosed, and it will be understood that the invention embraces all such changes and modifications in the parts and in the construction, combination and arrangement of parts as shall come within the purview of the appended claims.

i claim:

l. A means for holding a backed razor blade with resultant formation of a knife means; said holding means comprising a handle component including a hand grip portion and a blade holding portion formed as a longitudinal extension of the hand grip portion and having on one side thereof a bearing face for one side of a hacked razor blade and a socket in which the back component at said one side of the razor blade is received, a holding member overlying the blade engaging portion of said iandle component and including a bearing face engaging the opposite side of a razor blade positioned on said handle component with the back component thereof disposed in said socket; said holding member having a clearance cut therein for reception or" the opposite side of the razor lade back component, interenga ging means on said handle component and said holding means eflective to maintain them in aligned position; said blade engaging faces of said handle component and said holding means being similarly cut away to expose the end portion of the cutting edge of the razor blade, and spring clip means detachably securing said holding means and said handle component clampingly engaging a razor blade therebetween; said clip means including a resilient, slotted guard element normally guarding the exposed edge of a razor blade clamped between said handle component and said holding means.

2. A carton opening knife means employing a replaceably mounted razor blade comprising a handle component including a hand grip portion and a blade engaging portion formed as a longitudinal extension of said hand grip portion, a holding means detachably mounted on said blade engaging portion and eifecive to clamp a razor blade against said blade engaging portion of said handle means; said blade engaging portion of said handle component and said holding means having complementary portions cut away to expose an end portion of the razor blade edge, and a resilient guard element detachably carried by said handle component and said holding means normally extending beyond the exposed blade edge; said guard having a slot therein through which the blade is projected upon said guard being pressed against the side of a carton with resultant displacement of said guard from its normal position.

3. A knife means as claimed in claim 2 in which said guard includes spring clip means serving simultaneously to position said guard and to hold said handle component and said holding means clampingly engaging a razor blade therebetween.

4. A knife means as claimed in claim 2 in which said guard comprises a spring metal strip including a first portion extending longitudinally parallel to the edge of the razor blade thence extending in a second portion parallel to the end of the razor blade said guard at the end of said first portion remote from said second portion having opposed spring fingers engaging sockets formed in the outer faces of said handle component and said holding means and further having opposed spring fingers at the end of said second portion remote from said first portion slidingly engaging the outer faces of said handle component and said holding means. i

No references cited. 

